Carbureter.



L. s. GARDNER.

CARBURETER.

APPLICATION FILED LULY is. 1915.

Patented May 23,1916

INVENTOR.

PATENT QFFIE LEI/I S. GARDNER. OF DETROIT, MICHIGAN.

CARBURE'IER.

Application filed July 19, 1915.

To all whom. it may] concern:

Be it known that I, Iii-:vr S. GARDNER, a citizen of the United States. residing at De troit, county of \\'a vne. State of Michigan, have invented a certain new and useful Improvement in Carhureters, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being bad to the accompanying drawings. which form a part of this specification.

My invention has for its object to produce a caihureter consisting of a few simple parts which, without the employment of moving devices, shall operate effectively autoniatically to proportion the air and fuel so as to supply the most desirable mixtures at all speeds of the engine.

The various features of novelty whereby my invention is characterized will hereinafter he pointed out with particularity in the claims; but, for a full understanding oh my invention and of its object and advantages, reference may be had to the follow ng detailed description taken in connection with the accompanying drawing, wherein:

Figure 1 is an axial section through a carburetor arranged in accordance with a preferred form of my invention and Fig. 2 is I. section taken approximately on line 22 )f Fig. 1.

Referring to the drawing, 1 represents a .ubular member in the form of a Venturi nbe, forming the body of the carbuieter. Surrounding the lower end of the Venturi uhe is a suitable constant level reservoir, 2. \rranged axially within the member 1 is a .elivery tube, 3, whose open upper end ex ands slightly above the contracted neck, 4,

f the member 1. \Vith the particular arangeriient illustrated, and which I shall ereafter describe, I have found that the est results are obtained by making the inteor diameter of the member 3 approxiately one-third of the diameter of the conacted neck, 4, the member 3 being therefore uch larger than the ordinary nozzle. The wer end of the member 3 is bent laterally id is made to communicate in any suitable 1y with the interior of the fuel reservoir at point below the normal liquid level in the tter. In the arrangement shown, the mem r 3 is simply an. L-shaped pipe whose horintal leg fits into an opening in the wall Specification of Letters Patent.

Patented May M), 1916.

Serial No. 40,688.

of the member 1, the axis of the horizontal leg. being about in the plane 5 of the normal liquid level in the reservoir; :1 vertical passage. (5. extends up through the wall of the member 1 adjacent to the outer end of the tube 3: and the lower end of the passage 6 communicates with the interior of the reservoir through a plug, 7, having a restricted port or passage, 8, through the same. The passage (5 extends up beyond the plane of the top of the reservoir, and there communicates with the outside atmosphere through a port, 2), in a plug, 10; the diameter of the port 9 being less than the diameter of the passage 6 In the upper portion of the member 1 is the usual throttle valve, 11. From a point beside the upper end of the passage 6 to a point above the throttle valve is bored a passage, 12, preferably smaller in diameter than the passage, (3, and communicating with the latter by means of a very smallport or opening. 13.

through a port, 11, smaller in diameter than the passage 12 and larger in diameter than 'the passage or port, 13; the port 14 being arranged within a plug, 15. The upper end of the passage 12 communicates with the main air passage in the carhureter at a point which is constantly above the throttle valve; the throttle valve being arranged to swing in the direction of the arrow 16 when it is opened.

At low speeds of the engine, when the throttle valve is closed. a combustible mixture will be supplied through the passage 12. air entering through the tube 3 and through the ports 9 and 11, and suflicient fuel being picked up from the pool in the lower portion of the passage 6 to afford the proper mixture. It is possible, of course, that there is no downward flow through the tube 3 under the conditions specified, and I therefore do not wish to be understood as limiting myself to any particular theory of operation because the theory expressed above is simply one deduced from watching the successful operation of the carbureter. As the throttle is opened, the speed of the engine increasing, a gradually increasing suction in the Venturi tube will be created, air now flowing down through the passage 6 and across the pool of fuel and up out of the upper end of the tube 6 where, in the form of richly carbureted air, it connningles with The lower end of the passage 12 communicates with the outside atmospherethe main air charge which is being drawn into the engine. As the speed of the engine increases, the proportions between the total air and the total amount of fuel. passing through the carburetor are automatically varied so as to maintain the proper mixture at all times.

It is of course evident that the passages may be variously arranged and that the plugs 7, 10 and 15 are simply used for convenience and may be omitted if desired, as my invention consists of a few broad features independent of detail of form. Therefore, while I have illustrated and described with particularity only a single preferred form of my invention, I do not desire to be limited to the exact structural details thus illustrated and described; but intend to cover all forms and arrangements which come within the terms employed in the definitions of my invention constituting the appended claims.

I claim:

1. A carburetor comprising a. Venturi tube, a U-shaped tube having one arm lying at the axis of the Venturi tube and its other arm communicating with the outside atmosphere, and means for normally maintaining liquid fuel in said U-shaped tube at a level sufficiently low to leave an open passage above the same between the two arms of the tube. y

2. A carbureter comprising a Venturi tube, a delivery tube arranged axially of the Venturi tube and terminating at its upper end in the vicinity of the contracted neck of the latter, there being an opening leading from a point below the top of the delivery tube to the outside atmosphere and forming with the tube an air passage between the exterior and the interior of the carburetor, and means normally maintaining liquid fuel in said passage at a level sufiiciently low to ullOW air to flow freely above the same through said passage.

3. A carburetor comprising a Venturi tube, a delivery tube having a diameter about one-third as great as that of the contracted neck of the Venturi tube arranged axially in the latter and terminating at its upper end in the vicinity of said neck, means for normally maintaining liquid fuel in'the lower end of said delivery tube, and there being a passage leading to the outside atmosphere from a point in said delivery of the contracted neck of the latter, means for normally maintaining'the liquid fuel in the lower end of said delivery tube, there being a passage leading from a point in said delivery tube above the normal liquid level therein and communicating with the outside atmosphere through a port smaller in cross sectional area than said passage.

5. A carlnireter comprising a Venturi tube, a throttle valve in the upper end of the aforesaid tube, a delivery tube arranged axially of and terminating at its upper end in the vicinity of the contracted neck of the latter, means for normally maintaining the liquid fuel in the lower end of said delivery tube, there being a passage leading from a point in said delivery tube above the normal liquid level therein and communicating with theioutside atmosphere through a portsmaller in cross sectional area than said passage,

there being a second passage extending from a point adjacent to the aforesaid passage to a point above the throttle valve and communicating at its upper end with the main air passage in the carbureter, said second passage connnunicating with the outside atmosphere through a restricted port, and there being between the two passages a connecting passage smaller in cross sectional area than the last mentioned port.

(3. A carburetor comprising a Venturi tube, a constant level reservoir surrounding the lower end of said'tube, an Lshaped delivery tube having one arm arranged axially of the Venturi tube and the other arm extending out through the side of the latter, at least a portion of the latter arm being above the plane of the liquid level in the reservoir, there. being a passage connecting the horizontal arm of the delivery ,tube to the interior of the reservoir at a point below the liquid level, and there being a passage leading from the outer end of the horizontal arm of the delivery tube to the outside atmosphere.

In testimony whereof, I sign this specification.

LEVI S. GARDNER. 

